On the risk of making eyes roll by mentioning Solasta again, but:
what I especially like there is how the UI and its buttons segmented by action economy, and therefore fades out entire sections (not just grey out, but simply hide) of what a character can't do anymore after having taken their action / bonus action this turn already.
I'd hope BG3 can take pointers from that. It cleans up your choices efficiently for you during combat, makes combat turns much faster that way, and helps players to quickly develop an understanding of the action economy and what they can do (and when).
